Connecting device and method of making the same



March 2, 1948. E. v. SORENY' 2,

CONNECTING DEVICE AND METHOD OF MAKING THE SAME I Filed Aug. 15, 1943 ATYURNEY' Patented Mar. 2, i948 Ernest Soreny, New York, N. Y., assignor to Federal Telephone and Radio Corporation, Newark, N. J., a corporation of Delaware Application August 13, 1943, Serial No. 498,452

The present invention relates to electrical connecting devices and to a method of constructing the same.

Conventional plug and socket assemblies for joining two electrical circuits are designed in a number of ways. Usually both the plug and socket are formed with cylindrical walls of slightly different diameters so that a surfaceto-surface contact is obtained. It is also standard practice to have a plug receivable by a coiled spring which defines an opening of smaller diameter than the plug. In the latter instance the coiled spring may or may not be enclosedwithin a receptacle' An improvement over the above constructions is described in an application filed on August 9, 1943, by'George H. Erb, Serial Number 497,888. In the Eric application is disclosed a plug and socket assembly in which a single spring coiled in irregular fashion within a socket produces, upon insertion of a plug within the spring opening, a plurality of high-pressure points of contact between the spring and both the plug and the socket wall.

While the results obtained by the device disclosed in the above-mentioned Erb application are an improvement over prior art structures, it is desirable to obtain a greater contacting surface between the spring element and the socket Wall than is possible by an assembly constructed in the manner therein set forth. Moreover, while it is desired to efiect an increase in the contacting area and thus raise the current-conducting capacity of the assembly, it is at the same time desired to retain the high-pressure contacting 8 Claims. (01. 173-363) relation between'the spring member and its associated parts.

'The present invention, therefore, has as one object the provision of means for accomplishing the above mentioned desired results.

Another object of the present invention is to provide a spring assembly for use in an electrical connecting device, the assembly being composed of a plurality of individual spring units.

A further object of the invention is to provide a spring assembly for use in a connector, the assembly being formed of a plurality of irregularly shaped coil spring units which are interspersed so that each turn of the spring assembly is angularly disposed to a selected degree with the immediately. preceding convolution thereof.

A still further object of the invention is to provide a method of forming a spring wire contact assembly by interwinding the coils of two individual spring units.

Other objects and advantages will be apparent from the following description of a preferred form of the invention and from the drawings,

in which:

Fig. l is a top plan view, partly in section, of a preferred form of socket assembly in accordance with the present invention showing the Fig. 4 is a side view of a preferred form of plug for use with the socket assembly of Figs. 1 and 2. In the above mentioned application of George H. Erb the sprin insert member is designed to contact the inner wall of the socket at a plurality of points. These points may be of any number in excess of two for each convolution of the spring insert.

Assuming the maximum practical number of contact points, however, the current-conducting properties of the device would still be materially improved if the high pressure resulting from the "bowed type of construction could be retained while increasing the area of contact between the spring insert member and the receptacle wall.

This is accomplished in the preferred form of the invention hereinafter described by employing a coiled spring unit 6 consisting of two separate springs each pressed inwardly at two oppositely disposed points as best shown in Fig. 1. Since only about half the circumference of the individual springs is altered in shape, the resulting spring unit somewhat resembles an hourglass. Each spring may be shaped in any suitable manner, as by the method described and claimed in the aforementioned Erb application.

To produce the socket assembly of Figs. 1 and 2, a pair of springs having opposite, inwardly-bowed sections are utilized. The two springs are interwound or otherwise interspersed in any suitable manner to form the unit 6, with their respective bowed portions at right angles to one another.

When the interwound spring unit 6 has been assembled, it is placed in a socket 8 formed of conducting material and held in place in any.

suitable manner as by spinning over the top lip of the latter as shown at H). The cylindrical opening ll of the socket 8 receives a conductor which is held in place by any desired method such as soldering.

A plug l2, shown in Fig. 4, is designed to be received in the recess or opening I I of the assem- 3 bled spring unit 6 (Fig. 1). Since the plug has a diameter larger than the diameter of the recess, insertion of the plug will force apart the inwardlybowed sides of the individual springs and substantially increase the pressure between these springs and the inner wall of the socket 8. This increase'in pressure between the spring assembly and socket will lower the resistan'ce'oi the connector and reduce the tendency to overheating.

It will be seen that due to the particular shape of the individual springs, a large contacting area is obtained between the interwound spring member 6 shown in Figs. 1 and 2, and the inner'wall' of the socket 8. If wire of square cross-section is used to form the individual springs, then the possible contacting area will be considerably increased. Since each spring contacts the wall of socket B for approximately 180" of each convolution, the two interwound units forming the-member 6 will extend over nearly 360 of the socket wall as shown in Fig. 1. There are-also four points of contact between plug 12 and each combined turn of the spring member 6, so that the resulting device will be capable of conducting considerably higher currents than thosecarriedby the plug and socket assembly of the prior art.

While I have described above the principles of my invention in connection with a specific form of device, it is to be clearly understood that this description is made only by way of example and not as a limitation on the scope of my invention as set forth in the objects of my invention and the accompanying claims.

I claim:

1. In the manufacture of wire contacts for an electrical connector, the method which comprises forming wire into a pair of helices, producing a pair of oppositely-disposed inwardly-projecting indentations in each convolution of the helices, and interwinding the coils of the helices so that the indentations in each adjacent convolution of the interwound helices are disposed angularly to oneanother in planes substantially perpendicradar to the axis of the interwound. helices- 2. In an electrical connector of the type wherein a. plug. is receivable in the opening, of a tubular socket of conducting material, a pair of coiled spring wire members in said socket and contactingthe inner wall of the latter, the: configuration of each of said members having two oppositely-disposed inwardly-bowed portionsthe two. coiled-spring members being interwound. so that the inwardlwbowed portions of successive configurations of said membersare spaced approximately 89 apart in planes substantially perpendicular to the axis of said tubular socket, the said inwardly bowedportions defining a substantially rectangular opening align-ed sub stantially coaxially with said socket, whereby insertion of said plug in said. opening will compress. the inwardly bowed portions of said coiled spring members outwardly and'increase the. pressure of said members against theiinner walluof said socket.

3. In an electrical socket assembly, a socket of conducting material, and a pair of interwound coiled spring contact members within said socket, each convolution of each of said contact members' being sprung inwardly at a plurality of points, said contact members being interspersed so that the inwardly sprung portions of adjoining. convolutions of the two contact members are angularly disposed with respect to each other.

4. In an electrical connector, a socket formed of conducting material, and a pair of interwound coiled spring insert members in said socket, each turn of each of the said interwound coiled spring members having a plurality of inwardly-bowed portions. V

55in an electrical connector, 9. socket formed of conducting material, and a pair of interwound coiled spring insert members in said socket, each turn' of each of the said interwound coiled spring members having two oppositely-disposed inwardly-bowed portions.

6. In an electrical connector, 2. socket formed of conducting material, and a pair of interwound coiled spring insert members in said socket, each turn of each'oi the said interwound coiled spring members having two oppositely-disposed inwardly-bowed portions, the inwardly-bowed portions of adjoining convolutions of the said interwound spring members beingpositioned approxi mately relative to one another.

'1. A method of producing wire contacts for electrical connectors, comprising the steps of coiling resilient wire-intoa pair of. separate cylindrical helices, forming a pair of oppositely-disposed inwardly-projecting indentations in each convolution of the-helices, and interwinding the coils of the heiices so that the indentations. in eachadjacent coil of the interwound helices are disposed angularly to one another.

81A method of producing wire contact for electrical connectors, comprising the steps of coiling resilientntire into-aperir of separate helices, forming a pair of oppositely-disposed inwardly-projecting arcuate indentation in each convolution of eachhelix, interwindi-ng' the helices substantially throughout their lengths so that the arcuate indentations in each adjacent coil of the interwound helices are disposed angularly to one another.

- ERNEST V. 'SORENY.

Resonances orrno The "following references are of recordin the file of this patent:

UNITED STATES PATENTS Number Name Date 1,651,253 Fortin Janie, I928 232245.461 Challet July 19', 1938 2,246,489 Farkas- June24, 1941 FOREIGN PATENTS Number 7 Country Date.

105,795: Australia l Nov. 10, i938 Germany Apr. 29, 1.927 

